The age boys and girls start puberty has been gradually decreasing around the world.

In the UK, it is currently starting about one month earlier every decade. And the current average age is:

11 for girls

12 for boys

Image copyrightSolStock

Image caption
Children are starting puberty younger

Experts put this down to improved health and nutrition in the industrialised world – but studies have also shown a link between obesity and the early onset of puberty.

In 2015, a study indicated early or late onset of puberty were linked to a increased risk of:

diabetes

obesity

early menopause

cardiovascular disease

In girls, an early puberty was defined as starting between eight and 11, while a late puberty started between 15 and 19. In boys, a normal puberty started between nine and 14.

An American study in January suggested early puberty in girls was also linked to increased likelihood of mental health problems during adolescence and into adulthood.

“Both genetic and environmental factors undoubtedly influence puberty timing,” said Dr Christine Wohlfahrt-Veje, a researcher at the University of Copenhagen and one of the lead authors on a study in 2016 looking at puberty and timing.

“Boys and girls inherit from both mothers and fathers – but early pubertal markers, onset of breasts and pubic hair, in girls are less dependent on genetic and hence more on environmental factors such as childhood growth patterns and possibly other environmental exposures.”